Medical device

ABSTRACT

A mechanism for attaching a component, such as a speech processor unit ( 29 ) of a cochlear implant, to the clothing ( 40 ) of a user of that component. The attaching mechanism is operable by an unlocking device, such as a magnet ( 44 ), that can be held in the possession of a person other than the person wearing the clothing ( 40 ) to which the component is mounted. The attachment device can comprise an elongate pin member ( 33 ) that is adapted to pass through at least a portion of an item of clothing ( 40 ) and be received in a chamber ( 38 ) and held by frictional engagement therein.

TECHNICAL FIELD

The present invention relates to a medical device and more particularly,to a medical prosthesis.

BACKGROUND ART

The application of medical devices, such as hearing aids, implantablepacemakers, defibrillators, cochlear implants and other such functionalelectrical stimulation devices, are becoming more widespread as theiradvantages and benefits become more widely appreciated throughout thepopulation.

In particular, cochlear implants have been developed to assist peoplewho are profoundly deaf or severely hearing impaired, by enabling themto experience hearing sensation representative of the natural hearingsensation. In most such cases, these individuals have an absence of ordestruction of the hair cells in the cochlea which naturally transduceacoustic signals into nerve impulses which are interpreted by the brainas sound. The cochlear implant therefore bypasses the hair cells todirectly deliver electrical stimulation to the auditory nerves with thiselectrical stimulation being representative of the sound.

Cochlear implants have traditionally consisted of two main parts: aninternal part and an external part. The external part includes a speechprocessor unit and a transmitter coil. The internal part includes animplanted receiver/stimulator unit and an electrode array. The externalspeech processor unit is typically carried in a pouch or removablyclipped on the clothing, such as a belt, worn by the user using a clip.Its main purpose has been to detect sounds using a microphone and thenconvert the detected sound into a coded signal through an appropriatespeech processing strategy.

This coded signal is then sent to the receiver/stimulator unit, which istypically implanted in the mastoid bone of the user, via atranscutaneous radio frequency link. The receiver/stimulator unitprocesses this coded signal and outputs a series of stimulationsequences. These sequences are transmitted to appropriate electrodes ofan electrode array by respective electrically conducting wires. Thearray is positioned proximal to the modiolus of the cochlea such that anelectrical stimulus output by the electrodes is then applied to theauditory nerve.

For infants born with sensorineural hearing loss, studies indicate thatit is desirable to implant a cochlear implant as soon as possible afterbirth. This is because if an infant is to develop an ability tounderstand and process sounds such as speech, the brain must learn toreceive and process signals representative of sounds in the first fewyears of life.

A problem with infants and even small children is that small childrenare not aware of the importance of their external speech processor unitand often do not notice when the unit has become detached from theirclothing. Children are also naturally inquisitive and as they get olderwill often detach the speech processor unit from their clothing toexamine the unit or pass it among their friends. This often results inthe unit being mislaid. When a group of children having cochlearimplants play together it is also not unknown for these children todetach their external speech processor units and swap them with those oftheir friends. As the units are programmed to meet the hearing needs ofthat particular child, this often results in the unit being reported asfaulty by the parents or guardian of the child when in fact the child nolonger has their original unit. Further, the child can experience painand discomfort as a result of using a speech processor that has not beenprogrammed for their particular needs. Further, as children aretypically active, it is not uncommon for their external units to bedislodged during regular activity, which can result in the child losingthe unit or the unit becoming damaged or destroyed upon dislodgement. Asreplacement units are expensive and not readily available, such loss ordamage can result in the child being without the benefit of the devicefor extended periods of time until a replacement unit is available.

With regard to adults, it is common for many adult cochlear implantrecipients to prefer to use a body-worn external processor forparticular conditions, such as in a work or home environment, as opposedto a behind-the-ear processor which is more preferable when mobility andaesthetics is an issue. One of the main problems with body-wornprocessors is that they are often attached to the body by way of aremovable fastener, for example, a belt clip. Whilst such an attachmentmechanism allows the device to be easily removed when needed, it canalso be uncomfortable to wear and can often be inadvertently dislodgedthrough normal body movements, which can cause unnecessary irritation tosuch recipients. Further, a dropped processor can be very easilydamaged, resulting in inconvenience to the user while the unit is beingrepaired.

It is desirable to improve upon the above identified shortcomings.

Any discussion of documents, acts, materials, devices, articles or thelike which has been included in the present specification is solely forthe purpose of providing a context for the present invention. It is notto be taken as an admission that any or all of these matters form partof the prior art base or were common general knowledge in the fieldrelevant to the present invention as it existed before the priority dateof each claim of this application.

DISCLOSURE OF INVENTION

Throughout this specification the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated element, integer or step, or group of elements, integers orsteps, but not the exclusion of any other element, integer or step, orgroup of elements, integers or steps.

The present invention is directed to a mechanism for attaching acomponent to the clothing of a user of that component. In particular,the mechanism is operable by an unlocking device that can be held in thepossession of a person other than the person wearing the clothing towhich the component is mounted.

In one aspect, the present invention is a clothing attachment device foran external component of a hearing prosthesis, the attachment devicecomprising:

-   -   an elongate member adapted to pass through at least a portion of        an item of clothing; and    -   a receiving means adapted to receive at least a portion of the        elongate member and releasably engage therewith;    -   wherein at least one of said elongate member and said receiving        means are mountable to the external component and the engagement        of said elongate member and said receiving means is releasable        by an unlocking device.

In another aspect, the present invention is an external component of ahearing prosthesis, the external component comprising:

-   -   a casing;    -   a receiving means mounted to the casing; and    -   an elongate member adapted to pass through at least a portion of        an item of clothing and be received in the receiving means and        releasably engage therewith;    -   wherein the engagement of said elongate member and said        receiving means is releasable by an unlocking device.

In a still further aspect, the present invention is an externalcomponent of a hearing prosthesis, the external component comprising:

-   -   a casing;    -   an elongate member extending outwardly from the casing and        adapted to pass through at least a portion of an item of        clothing; and    -   a receiving means adapted to receive at least a portion of the        elongate member and releasably engage therewith;    -   wherein the engagement of said elongate member and said        receiving means is releasable by an unlocking device.

In these aspects, the hearing prosthesis preferably comprises a cochlearimplant. In this case, the external component preferably comprises aspeech processor unit for receiving signals from a microphone andconverting the detected sound into a coded signal through an appropriatespeech processing strategy.

In one embodiment, the elongate member can comprise a pin memberextending from a proximal end to a distal end. Where the elongate memberextends outwardly from the casing of the external component, the pin canbe integrally connected to the casing, permanently mounted thereto, orreleasably mountable thereto.

In another embodiment, the elongate member can comprise a head and a pinmember extending from the head to a distal end.

Where the elongate member has a head, the head can be formed integrallywith the pin member or formed separately and then attached thereto. Thepin member is preferably formed of a metal, such as stainless steel. Thehead can be formed of a metal and/or a plastics material.

In one embodiment, the head comprises a disc, such as a circular disc,having a diameter greater than that of the pin member. The head memberpreferably has a diameter at least 10 and preferably greater than 20times the diameter of the pin member. The disc is preferably relativelyflat and has an underside that is adapted, in use, to be positionedagainst the clothing.

The distal end of the pin member can have a tapered or pointed end toassist in the passage of the pin member through an item of clothing. Itis also envisaged that the distal end of the pin member could also beblunt or rounded in certain situations, for example to avoid sharpimplements being used with regard to young children.

In a preferred embodiment, the receiving means is adapted to be mountedto the casing of the speech processor unit of the hearing prosthesis. Inone embodiment, the receiving means can be non-removably mounted to thecasing. In another embodiment, the receiving means can be removablymounted to the casing.

The receiving means preferably comprises an orifice extending into thereceiving means from a front surface thereof. The orifice is able toreceive at least a portion of the length of the elongate member. Theorifice extends from the front surface to a chamber within the receivingmeans. The orifice can be tubular. In another embodiment, the orificecan be circular in cross-section.

The chamber of the receiving means preferably has an inner wall of whichat least a portion thereof is frusto-conical such that the chamberexpands in diameter away from the front surface of the receiving means.In a preferred embodiment, the inner wall is frusto-conical over itsentire length from a forward end to a rearward end of the chamber.

The receiving means can further comprise a pin engagement mechanismadapted to frictionally engage the pin member on insertion of the pinmember through the orifice and into the chamber.

In one embodiment, the pin engagement mechanism can comprise a pluralityof engagement members disposed in at least a substantially circulararrangement within the chamber. In one embodiment, the engagementmembers can comprise spherical members or balls, such as ball bearings.At least one, and preferably all, of the spherical members or balls arepreferably formed from a metallic material, still more preferably amagnetic material. The engagement members, such as the sphericalmembers, are preferably normally positioned in an engaging configurationwithin the chamber. This configuration is preferably provided by abiasing means positioned within the chamber and which when in itsrelaxed condition displaces the engagement members towards the forwardend of the chamber. The frusto-conical wall of the chamber serves tocompress the engagement members towards each other as they are biasedtowards the front surface of the receiving means. On insertion of thepin member into the receiving means, the pin member can be insertedbetween the respective inwardly facing surface portions of theengagement members. The members in the engaging configuration do thoughprovide sufficient frictional engagement with the pin member to preventits withdrawal therefrom by at least a child, and even preferably anadult.

In one embodiment, the biasing means can comprise a spring, such as aspiral spring. The spring is preferably adapted to urge a plate againstthe engagement members within the chamber and so hold them in theengaging configuration. In one embodiment, the spring is mounted betweenthe rearward end of the chamber and the plate, the plate being mountedto the forward end of the spring. In another embodiment, the biasingmeans can comprise a compressible elastomeric material.

As defined, an unlocking device is used to disengage the elongate memberfrom the receiving means. In one embodiment, such as where the receivingmeans utilises the engagement members to provide frictional engagementwith the pin member, the unlocking device can comprise a magnet that canbe brought adjacent the rearward surface of the receiving means. Themagnet preferably has a magnetic field of a strength sufficient toovercome the bias provided on the spheres by the biasing means and socause the metallic engagement members to move rearwardly relative to thechamber. As the members move relatively rearwardly, the increase indiameter of the chamber serves to allow them to move relatively apartand so remove the frictional engagement between them and the pin memberand allowing the pin member to be withdrawn from the receiving means.

Where the hearing prosthesis is being worn by a child, the magnet may bekept in the possession of a supervising adult, such as a parent orguardian. When the external component is to be removed from theclothing, the magnet can be retrieved, and used to disengage the pinmember from the receiving means. When the prosthesis is to be usedagain, the option is open to pass the elongate member through an item ofclothing and then into the orifice and chamber of the receiving means.It is preferred that the bias provided by the biasing means is of astrength that allows a typical adult to insert the pin into thereceiving means with the result that it is engaged by the engagementmembers without the necessity to firstly use the magnet to withdraw themembers prior to insertion. It will be appreciated that in anotherembodiment, this could be a requirement for successfully engaging thepin member to the receiving means.

In accordance with another aspect of the present invention, there isprovided an external component of a medical device, the externalcomponent comprising:

-   -   a casing;    -   an elongate member having a disc and a pin member adapted to        pass through at least a portion of an item of clothing; and    -   a pin member engagement device having a plurality of spheres        disposed in a circular arrangement within a chamber, the chamber        having an inner wall, of which at least a portion is        frusto-conical such that the chamber expands in diameter away        from a front surface of the engagement device, the pin        engagement device also having a spring acting and mounted        between a rearward end of the chamber and a plate, the spring        being adapted to urge the plate against the spheres within the        chamber;    -   wherein an orifice is formed in the engagement device to enable        entry of the pin member into the chamber and thereafter        frictionally engage with the plurality of spheres, the        engagement of the pin being releasable by a magnet having a        magnetic field of a strength sufficient to overcome the bias        provided on the spheres by the spring and so cause the spheres        to move rearwardly relative to the chamber.

In accordance with yet another aspect of this disclosure, there isprovided an external component of a medical device, the externalcomponent comprising:

-   -   a casing;    -   an elongate member extending outwardly from the casing and        adapted to pass through at least a portion of an item of        clothing; and    -   a receiving means adapted to receive at least a portion of the        elongate member and releasably engage therewith;    -   wherein the engagement of said elongate member and said        receiving means is releasable by an unlocking device.

In accordance with yet another aspect of this disclosure, there isprovided an external component of a medical device, the externalcomponent comprising:

-   -   an elongate member;    -   a retaining means for frictionally retaining at least a portion        of the elongate member in a first configuration and for        releasing the at least one portion in a second configuration;        and    -   a biasing means for biasing the retaining device into the first        configuration;    -   wherein the retaining means is incorporated into the external        component to enable the external component to be fastened to an        item of clothing worn by a user of the external component, when        the retaining means is frictionally retaining the at least a        portion of the elongate member. Preferably, the elongate member        is releasable from the retaining means by momentarily        counteracting the biasing means to cause the retaining means to        assume the second configuration.

BRIEF DESCRIPTION OF DRAWINGS

By way of example only, a preferred embodiment of the invention is nowdescribed with reference to the accompanying drawings, in which:

FIG. 1 is a simplified pictorial representation of a prior art cochlearimplant system;

FIG. 2 is a simplified, partial sectional view of one embodiment of aclothing attachment device within an external speech processing unitaccording to the present invention;

FIG. 3 is a view of the clothing attachment device of FIG. 2 with theexternal speech processing unit being ready to attach to an item ofclothing;

FIG. 4 is a view of the clothing attachment device of FIG. 2 depictingthe external speech processor unit of a cochlear implant prosthesisattached to an item of clothing;

FIG. 5 is a view of the clothing attachment device of FIG. 2 followingdisengagement of the external speech processor unit from the clothing;

FIG. 6A is a perspective view of the external speech processor unit ofFIGS. 2 to 5;

FIG. 6B is the external speech processor unit of FIG. 6A attached to anitem of clothing;

FIG. 7A is a perspective view of an alternative external speechprocessor unit;

FIG. 7B is the external speech processor unit of FIG. 7A attached to anitem of clothing;

FIGS. 8A to 8D are views of a clothing attachment device according to analternative configuration;

FIG. 9 is a perspective view of an external speech processor unitaccording to an alternative configuration;

FIG. 10 is a horizontal section through the external speech processorunit of FIG. 9; and

FIG. 11 is a simplified, partial section view of a clothing attachmentdevice according to an alternative configuration.

BEST MODE FOR CARRYING OUT THE INVENTION

While it is to be understood that the present invention has widerapplication, the invention will be hereinafter described with referenceto its application to mounting a speech processor of a cochlear implantto the clothing of a user of the implant.

Before describing the features of the present invention, it isappropriate to briefly describe the construction of one type of knowncochlear implant system with reference to FIG. 1.

A cochlear implant typically consists of two main components, anexternal component including a speech processor unit 29, and an internalcomponent including an implanted receiver and stimulator unit 22. Theexternal component includes a microphone 27. The speech processor unit29 is, in this illustration, constructed and arranged to be clipped tothe clothing of a recipient with the use of a clip 30, or carried in apouch worn by the recipient. In the depicted arrangement, a transmittercoil 24 receives signals from the speech processor 29 through cable 5which in turn transmits signals to the implanted unit 22 via a radiofrequency (RF) link.

The implanted component includes a receiver coil 23 for receiving powerand data from the transmitter coil 24. A cable 21 extends from theimplanted receiver and stimulator unit 22 to the cochlea 6 andterminates in an electrode carrier 20. The signals thus received areapplied by the electrodes of the carrier 20 to the basilar membrane 8thereby stimulating the auditory nerve 9.

Turning to FIG. 2, a portion of an external speech processor unit 45having a clothing attachment device 46 is depicted, the clothingattachment device 46 being incorporated into a body or casing 47 of theexternal speech processor unit 45. The clothing attachment device 46includes a pin engagement device 31 that is adapted to receive andretain an elongated member in the form of a pin 33. Preferably, the pin33 is frictionally engaged with the pin engagement device 31. Theelongate portion 32 of the depicted pin 33 is formed from stainlesssteel, with a portion of the elongate portion 32 tapering adjacent to adistal end 35 to assist in passage of the pin 33 through an item ofclothing 40. The elongate portion 32 may also be blunt adjacent thedistal end 35, to the extent that the weave of an intended clothingfabric will allow the pin to pass through. Such a blunt end could bedesirable for the sake of child safety.

As depicted, the pin 33 can have a relatively flat disc-shaped head 34,the outside surface of which normally sits against the skin of the user.The head 34 has the elongate portion 32 extending therefrom to thedistal end 35. The head 34 is formed of stainless steel material,however the head 34 could also be formed of a polymeric material orother suitable material. The diameter of the pin head is in the order of1.25 mm. The depicted head 34 has a diameter at least 10 times that ofthe diameter of the elongate portion 32 and so is around 12.5 mmdiameter.

It will be appreciated that in another arrangement, the elongate portion32 could extend outwardly from the casing 47 of the processor unit 45with the engagement device 31 being free, as shown in FIG. 7A. Thisarrangement could be suitable where the external speech processor unit29 is regularly carried in a pocket 70, as shown for example in FIG. 7B.Referring now to FIG. 3, the pin engagement device 31 has an orifice 36extending into the processor unit 29 from a front surface 37 of the pinengagement device 31. The pin engagement device 31is able to receive atleast a portion of the length of the elongate portion 32 of the pin 33.As depicted, the orifice 36 extends from the front surface 37 to achamber 38.

The chamber 38 has a frusto-conical inner wall 39 such that the chamber38 expands in diameter away from the front surface 37. Disposed withinthe chamber 38 is a pin engagement mechanism in the form of a pluralityof metallic spheres 41, or ball bearings. These spheres 41 are disposedin a generally circular arrangement, although they need not necessarilybe all touching one another, within the chamber 38. The spheres 41 arenormally positioned toward the front of the chamber 38 in an engagingconfiguration as is depicted in FIG. 3. This configuration is providedby a biasing spring 42 that is positioned within the chamber 38 andwhich, when in its relaxed condition, displaces the spheres 41 towardsthe forward end of the chamber 38. This engaging configuration ismaintained regardless of the physical orientation of the attachmentdevice 46, due to the action of the spring 42. The frusto-conical wall39 of the chamber 38 serves to compress the spheres 41 towards eachother as the spheres 41 are pushed by the spring 42 towards the frontsurface 37. In the depicted embodiment, the front surface 37 is thatsurface of the attachment device 46 which abuts with the clothing 40.

On insertion of the elongate portion 32 of the pin 33 into the orifice36, the elongate portion 32 can be inserted between the respective innersurfaces of the spheres 41. As depicted in FIG. 4, the insertion of thepin 33 results in the spheres 41 being moved relatively rearwardly arelatively small distance within the chamber 38. The spheres 41 are nowarranged in the engaging configuration through the biasing action of thespring 42 and provide sufficient frictional engagement with the elongateportion of the pin 33 to prevent its withdrawal therefrom by a child,and even preferably an adult.

As depicted, the spring 42 urges a plate 43 against the spheres 41within the chamber 38 and so holds the spheres 41 in the engagingconfiguration, no matter what orientation the chamber is arranged e.g.,upside down, sideways or other.

The pin 33 can be incrementally inserted and retained in the pinengagement device 31, thus enabling various different thicknesses ofclothing to be used.

Once the pin 33 is inserted into the engagement device 31, it serves tosecurely fasten of the unit 47 to the clothing 40 as is depicted inFIGS. 4, 6A and 6B.

To disengage the pin 33 from the engagement device 31, a magnet 44 canbe brought adjacent the rearward end or surface of the device 31 as isdepicted in FIG. 5. The magnet 44 is made up of several permanentmagnets arranged together in a convenient, portable housing. The magnet44 has a magnetic field of a strength sufficient to overcome the biasprovided on the spheres 41 by the spring 42 and so cause the spheres 41and the plate 43 to move rearwardly relative to the chamber 38. As thespheres 41 move relatively rearwardly, the increase in diameter of thechamber 38 serves to allow the spheres to also move apart sufficientlyto remove the frictional engagement between the spheres 41 and the pin33 and so allow the pin 33 to be withdrawn from the engagement device31. The pin engagement device 31 is then ready to be used again whenrequired.

In one example, the strength of magnetic field required by the magnet 44was in the range of 0.689 kGauss (with 6 mm air gap) to 0.838 k Gauss(with 6 mm air gap). This example used a pin having a head ofapproximately 12 mm diameter and a pin member of approximately 1.25 mmdiameter. Importantly, the magnetic field must be matched to theconstruction of the pin engagement device 31 so that the biasing actionof the spring 42 can be counteracted to the extent required to enablethe engagement device 31 to release the pin 33.

Where the cochlear implant is being worn by a child, the magnet 44 canbe kept in the possession of a supervising adult, such as a parent orguardian. When the processor unit 45 is to be removed from the clothing40, the magnet 44 can be retrieved, and used to disengage, or releasethe pin 33 from the engagement device 31. When the prosthesis is to beused again, the option is open to pass the pin 33 through an item ofclothing 40 and then into the orifice 36 and chamber 38. It is preferredthat the bias provided by the spring 42 is of a strength that allows atypical adult to insert the pin into the device with the result that itis engaged by the spheres 41 without the necessity to firstly use themagnet 44 to withdraw the spheres 41 prior to insertion. It will beappreciated that in another embodiment, this could be a requirement forsuccessfully engaging the pin 33 to the engagement device 31.

An alternative arrangement is shown in FIGS. 8A to 8D in which therearward movement of the spring 42 is limited by the dimensions of theplate 85. This allows the plurality of spheres to be replaced withengagement members of a different shape. This is because there is noneed for spheres which can naturally realign themselves after beingallowed to freely move in the space created at the front of the chamberwhen the pin is disengaged and the spring is fully counteracted by themagnet. Instead, the plate in FIGS. 8A to 8D limits the space createdwhen the pin is disengaged and thus, the movement of the engagementmembers is minimised. Accordingly, the pin engagement members of FIGS.8A to 8D are in the form of a pair of semi-circular elements 81, 82.Thus, when the members are urged together as shown in FIGS. 8A and 8B, africtional engagement with a pin can be achieved. The limitation of therearward movement keeps the members 81, 82 aligned and ready to bepushed into the engagement configuration when required.

FIG. 9 shows an alternative configuration in which the elongate membercomprises one or more flat members 94, 95. In this case, the elongatemember is a U-shaped member 90 arranged be slotted into a receivingdevice 96 co-operatively configured within the speech processor unit 91.

Referring to FIG. 10, the biasing means is provided by way of a pair ofsprings 92, 93, each of which act on a ball bearing at their respectiveends. Each of the ball bearings are arranged to engage with a hole ineach of the legs of the flat members 94, 95 and thus engage the U-shapedmember 90 in the receiving device 96. When it desired to disengage theU-shaped member 90 from the receiving device 96, each spring can becounteracted by the action of an external magnet, thus retracting theball bearing from the holes 94, 95 and releasing the U shaped member 90.

FIG. 11 shows an alternative configuration to the biasing means, orspring described in relation to FIGS. 2 to 5. In FIG. 11, the spring isreplaced with a compressible elastomeric material 110. Since the meansby which the biasing occurs is not a magnetic material (unlike thespring, which is preferably metal), the magnetic characteristics of theplate 111 and the pin engagement device 112 need to be taken intoaccount to ensure that the external magnet will exert enoughcounteractive force to the material 110 to unlock the pin 33.

The mechanism described herein ensures a speech processor unit of acochlear implant remains in place and secured to the clothing of a childwearer, particularly an infant. This has particular advantage inensuring the processor unit is not inadvertently lost and also has thepotential to reduce the likelihood of damage to the processor unitduring normal play and activities of a child or infant.

Further, the mechanism can be made small and relatively unobtrusive tothe wearer of the external component.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the invention as shown inthe specific embodiments without departing from the spirit or scope ofthe invention as broadly described. For example, the clothing attachmentmechanism could be applied to a medical prosthesis such as a pacemakeror other functional electrical systems (FES) such as for spinalstimulation.

The present embodiments are, therefore, to be considered in all respectsas illustrative and not restrictive.

1. A clothing attachment device for an external component of a hearingprosthesis, the attachment device comprising: an elongate member adaptedto pass through at least a portion of an item of clothing; and areceiving means adapted to receive at least a portion of the elongatemember and releasably engage therewith; wherein at least one of saidelongate member and said receiving means are mountable to the externalcomponent and the engagement of said elongate member and said receivingmeans is releasable by an unlocking device.
 2. The clothing attachmentdevice of claim 1 wherein the elongate member is a pin member extendingfrom a proximal end to a distal end.
 3. The clothing attachment deviceof claim 2 wherein the pin member extends outwardly from a casing of theexternal component to its distal end.
 4. The clothing attachment deviceof claim 3 wherein the proximal end of the pin member is integrallyconnected to the casing.
 5. The clothing attachment device of claim 1wherein the elongate member comprises a head and a pin member extendingfrom the head to a distal end.
 6. The clothing attachment device ofclaim 1 wherein the receiving means is mounted to a casing of theexternal component.
 7. The clothing attachment device of claim 6 whereinthe receiving means comprises an orifice extending into the receivingmeans from a front surface thereof, the orifice being able to receive atleast a portion of the length of the elongate member.
 8. The clothingattachment device of claim 7 wherein the orifice extends from the frontsurface to a chamber within the receiving means.
 9. The clothingattachment device of claim 8 wherein the chamber of the receiving meanshas a inner wall of which at least a portion thereof is frusto-conicalsuch that the chamber expends in diameter away from the front surface ofthe receiving means.
 10. The clothing attachment device of claim 9wherein the receiving means further comprises a pin engagement mechanismthat frictionally engages the pin member on insertion of the pin memberthrough the orifice and into the chamber.
 11. The clothing attachmentdevice of claim 10 wherein the pin engagement mechanism comprises aplurality of engagement members disposed in at least a substantiallycircular arrangement within the chamber.
 12. The clothing attachmentdevice of claim 11 wherein at least one of the engagement members is ametallic spherical member.
 13. The clothing attachment device of claim12 wherein all of the engagement members are metallic spherical members.14. The clothing attachment device of claim 12 wherein the engagementmembers are normally biased in an engaging configuration within thechamber.
 15. The clothing attachment device of claim 14 wherein abiasing means is positioned within the chamber which, when in itsrelaxed condition, displaces the engagement members towards the frontsurface of the receiving means and into the engaging configuration. 16.The clothing attachment device of claim 15 wherein the biasing means isa spring and plate, the spring being mounted between a rearward end ofthe chamber and the plate, and the plate being mounted to a forward endof the spring.
 17. The clothing attachment device of claim 16 whereinthe unlocking device is a magnet having a magnetic field of a strengthsufficient to overcome the bias provided on the engagement members bythe biasing means and so cause the engagement members to move rearwardlyrelative to the chamber when brought adjacent a rear surface of thereceiving means.
 18. The clothing attachment device of claim 1 whereinthe hearing prosthesis is a cochlear implant.
 19. An external componentof a medical device, the external component comprising: a casing; areceiving means mounted to the casing; and an elongate member adapted topass through at least a portion of an item of clothing and be receivedin the receiving means and releasably engage therewith; wherein theengagement of said elongate member and said receiving means isreleasable by an unlocking device.
 20. The external component of claim19, wherein the medical device is a cochlear implant.
 21. An externalcomponent of a medical device, the external component comprising: acasing; an elongate member having a disc and a pin member adapted topass through at least a portion of an item of clothing; and a pin memberengagement device having a plurality of spheres disposed in a circulararrangement within a chamber, the chamber having an inner wall, of whichat least a portion is frusto-conical such that the chamber expands indiameter away from a front surface of the engagement device, the pinengagement device also having a spring acting and mounted between arearward end of the chamber and a plate, the spring being adapted tourge the plate against the spheres within the chamber; wherein anorifice is formed in the engagement device to enable entry of the pinmember into the chamber and thereafter frictionally engage with theplurality of spheres, the engagement of the pin being releasable by amagnet having a magnetic field of a strength sufficient to overcome thebias provided on the spheres by the spring and so cause the spheres tomove rearwardly relative to the chamber.
 22. An external component of amedical device, the external component comprising: a casing; an elongatemember extending outwardly from the casing and adapted to pass throughat least a portion of an item of clothing; and a receiving means adaptedto receive at least a portion of the elongate member and releasablyengage therewith; wherein the engagement of said elongate member andsaid receiving means is releasable by an unlocking device.
 23. Theexternal component of claim 22, wherein the medical device is a cochlearimplant.
 24. An external component of a medical device, the externalcomponent comprising: an elongate member; a retaining means forfrictionally retaining at least a portion of the elongate member in afirst configuration and for releasing the at least one portion in asecond configuration; and a biasing means for biasing the retainingdevice into the first configuration; wherein the retaining means isincorporated into the external component to enable the externalcomponent to be fastened to an item of clothing worn by a user of theexternal component, when the retaining means is frictionally retainingthe said at least a portion of the elongate member.
 25. The externalcomponent of claim 24, wherein the elongate member is releasable fromthe retaining means by momentarily counteracting the biasing means tocause the retaining means to assume the second configuration.
 26. Theexternal component of claim 25, wherein at least a part of the retainingmeans comprises a magnetic material and the biasing means iscounteracted by applying a magnetic field to the at least a part of theretaining means.
 27. The external component as claimed in claim 26,wherein the biasing means is a spiral spring.
 28. The external componentas claimed in claim 27, wherein the retaining means comprises aplurality of spheres disposed in a substantially circular arrangementwithin a chamber.
 29. The external component of claim 28, wherein thehearing prosthesis is a cochlear implant.